Justin Yoshimura knows as much. The 24-year-old angel investor and founder and CEO of 500friends — a service that helps online retailers reward loyal shoppers — has experienced the challenges of entrepreneurship.

Before growing his company into a top software-as-a-service loyalty program, Yoshimura witnessed the ups and downs of the startup world, from struggling to meet payroll to bootstrapping a company to more than $10 million in revenues.

On Thursday at 6:3o p.m., he will share some of the lessons he learned in a discussion with myself, San Francisco Chronicle business editor Ben Muessig, at General Assembly, as part of the Changemakers Under 30 series.

Have any questions for Justin? Leave them in the comments and I’ll throw them his way.

General Assembly is located at 20 Rausch St., between Howard and Folsom streets.

An earlier version of this post said Yoshimura dropped out of high school at 14 — he started his company at 14 but didn’t drop out until he was 15.